Assuming you have folders for where each component will go

ITCSS.css

/* ITCSS — Inverted Triangle CSS 
   
   Solving CSS specificity problems one file at a time.
*/

/* Settings */
/* Set default values like color and typography here */
@import "settings";

/* Tools */
/* More relevant in SCSS (Sass), but put any tools or mixins (Sass) here */

/* Generic */
/* Any reset or normalization goes here. Setting the CSS settings. */

/* Elements */
/* Any raw HTML element are styled here */
@import "elements";

/* Objects */
/* Any specific object or shared component in the HTML
ex: stuff like a `layout`, `container`, `drawer` */
@import "objects";

/* Components */
/* More specific objects
ex: `about`, `header`, `footer`, `avatar` */
@import "components";

/* Utilities */
/* Any special override */
@import "utilities";